The present invention relates to an exposure apparatus used in a semiconductor manufacturing process and, more particularly, to a linear motor which is suitable for a projection exposure apparatus for projecting and transferring a reticle pattern onto a silicon wafer, and is suitable for moving a reticle and wafer on reticle and wafer stages for sequentially moving the reticle and silicon wafer with respect to a projection exposure system when projecting a reticle pattern onto the wafer.
The present invention relates to a linear motor suitable for transmitting the reaction forces of the reticle and wafer stages of an exposure apparatus, or a linear motor suitable for damping that is set on the mount of a main body structure which supports each stage and a projection optical system.
FIGS. 17A and 17B schematically show the coil of a linear motor and a coil fixing method in a conventional exposure apparatus. FIG. 17A is a plan view, and FIG. 17B is a cross-sectional view. As shown in FIG. 16, a coil 116 uses a round wire coil 116a, and is constituted such that a round wire obtained by covering an insulating a copper wire 116b with an insulating layer 116c of polyimide or the like is wound into a corner-rounded rectangular shape. The coil 116 has a hollow structure. In other words, the inside of the conductor-wounded coil 116 is hollow like a so-called doughnut shape.
The coil 116 is fixed to a linear motor main body by fitting positioning portions 154 in the hollow coil portion. In general, the coil positioning precision greatly influences the thrust performance of a linear motor, so the positioning precision required to fix a coil is very strict. Particularly, a linear motor used for nm-order positioning in an exposure apparatus or the like often requires a coil fixing precision of 100 xcexcm or less. Along with recent increases in the output and efficiency of linear motors, the linear motors are using a foil coil wounded with a copper foil-like film with which the coil wire moment can be designed higher than with a round wire.
A linear motor used in an exposure apparatus together with a hollow coil has a structure as shown in FIGS. 15A and 15B. In FIGS. 15A and 15B, a plurality of coils 116 are aligned within an effective stroke in the driving direction of a linear motor 109, and the lead line of each coil 116 is connected to a connector 118. A member movable with respect to the linear motor stationary member incorporates movable magnets 119. By flowing a driving current through the coils 116, the movable magnets 119 magnetized by a Lorentz force as shown in FIG. 15B are moved in a moving direction indicated by the arrow. This linear motor is used for a wafer stage or the like in an exposure apparatus.
The structure using the hollow portion of a hollow coil for coil positioning, like the above prior art, suffers the following problems.
1. In order to precisely fix the coil to the linear motor main body, the dimensional precision of an inner coil surface must be increased. The inner coil surface is made of a wire, so the dimensional precision must be increased by grinding the inner coil surface. If the dimensional precision does not increase, it adversely affects the positioning precision of a positioning device and the exposure precision of an exposure apparatus. To prevent this, the winding precision must be very strict even in winding a wire, which poses technical and cost problems.
2. In forming a coil, a wire is wound around a winding jig (to be referred to as a core member hereinafter) having a shape corresponding to an inner coil shape. Then, the core member is removed. However, it is technically difficult and costly to remove the core member while keeping high dimensional precision of the inner coil surface.
3. Even if problems 1 and 2 are solved and a high-precision coil can be formed, the wire may be damaged in assembling the coil into a linear motor housing. Although the positioning precision for fixing the coil must be high, the coil must be loosely fitted on the linear motor housing. Thus, the coil and exposure apparatus cannot ensure high reliability.
When a round wire is wounded as a coil wire, like the prior art, the strength and rigidity of the wire are relatively high, and the above problems hardly occur. As for a coil wounded with a foil-like conductor, the wire itself readily deforms and is damaged. The above problems cause an insulation failure. From this, demands have strongly arisen for a foil coil structure which can be securely assembled into a linear motor housing with high yield.
The present invention has been proposed to solve the conventional problems, and has as its object to provide an exposure apparatus and a linear motor suitable for the same that can increase coil fixing/positioning precision, workability in assembling a coil into a linear motor housing, exposure speed, and reliability.
To achieve the above object, a linear motor according to the present invention provides a core member; a coil obtained by winding a foil-like conductor having an insulating layer around the core member in a multilayered structure; and a coil fixing portion fixing the coil, wherein the coil is fixed to the coil fixing portion by using the core member.
In the linear motor according to the present invention, the core member is preferably formed from an insulating material.
In the linear motor according to the present invention, the core member is preferably formed from a material having a low thermal conductivity.
In the linear motor according to the present invention, the core member is preferably formed from the same material as a material of the coil fixing portion or a material having substantially the same linear expansion coefficient.
In the linear motor according to the present invention, the core member is preferably formed from a ceramic.
In the linear motor according to the present invention, the core member is preferably formed from a resin material.
In the linear motor according to the present invention, the core member is preferably annular and is fixed by being fitted on the coil fixing portion.
In the linear motor according to the present invention, preferably an outer circumferential surface of the coil wounded with the foil-like conductor in the multilayered structure is covered with an electrically insulating material.
In the linear motor according to the present invention, the coil fixing portion is preferably shaped such that an area in a direction in which a large force is received under influence of a magnetic field is larger than an area in a direction in which a small force is received.
In the linear motor according to the present invention, preferably, the core member also serves as a winding jig used to form a coil.
To achieve the above object, a method of manufacturing a linear motor according to the present invention comprises a step of causing a core member of the linear motor to serve as a winding jig and winding a foil-like conductor around the core member; and a step of manufacturing the linear motor by using the core member as part of a coil after the winding step, wherein the linear motor includes a core member, a coil obtained by winding the foil-like conductor having an insulating layer around the core member in a multilayered structure, and a coil fixing portion fixing the coil, and the coil is fixed to the coil fixing portion by using the core member.
An exposure apparatus according to the present invention comprises a reticle stage scanning a reticle; a wafer stage scanning a wafer; a projection optical system arranged so that the reticle scanned is projected on the wafer scanned via the optical unit; and a linear motor being used in the apparatus having, (i) a core member, (ii) a coil obtained by winding a foil-like conductor having an insulating layer around the core member in a multilayered structure; and (iii) a coil fixing portion fixing the coil, wherein the coil is fixed to the coil fixing portion by using the core member.
In the exposure apparatus according to the present invention, the linear motor is preferably used as at least either one of a force actuator in a driving unit driving the reticle stage and the wafer stage or in a reaction force receiving unit for cutting off transmission of a reaction force in driving the stage, and means for preventing vibration transmission in a support unit for the wafer stage and a support unit for the optical unit.
In the exposure apparatus according to the present invention, a beam used preferably includes a light ray and an electron beam emitted via a projection optical system.
A semiconductor device manufacturing method according to the present invention comprises the steps of: installing a plurality of semiconductor manufacturing apparatuses including an exposure apparatus in a semiconductor manufacturing factory; and manufacturing a semiconductor device by using the plurality of semiconductor manufacturing apparatuses, wherein the exposure apparatus includes a reticle stage scanning a reticle; a wafer stage scanning a wafer; a projection optical system arranged so that the reticle scanned is projected on the wafer scanned via the optical unit; and a linear motor being used in the apparatus having, (i) a core member, (ii) a coil obtained by winding a foil-like conductor having an insulating layer around the core member in a multilayered structure; and (iii) a coil fixing portion fixing the coil, wherein the coil is fixed to the coil fixing portion by using the core member.
The semiconductor device manufacturing method according to the present invention, further comprises the steps of: connecting the plurality of semiconductor manufacturing apparatuses via a local area network; connecting the local area network to an external network outside the semiconductor manufacturing factory; acquiring information about the exposure apparatus from a database on the external network by using the local area network and the external network; and controlling the exposure apparatus on the basis of the acquired information.
In the semiconductor device manufacturing method according to the present invention, a database provided by a vendor or user of the exposure apparatus is preferably accessed via the external network, thereby obtaining maintenance information of the exposure apparatus by data communication, or data communication is performed between the semiconductor manufacturing factory and another semiconductor manufacturing factory via the external network, thereby performing production management.
A semiconductor manufacturing factory according to the present invention comprises a plurality of semiconductor manufacturing apparatuses including an exposure apparatus; a local area network connecting the plurality of semiconductor manufacturing apparatuses; and a gateway for allowing access to an external network outside the factory from the local area network and allowing communicating information about at least one of the plurality of semiconductor manufacturing apparatuses, wherein the exposure apparatus includes a reticle stage scanning a reticle; a wafer stage scanning a wafer; a projection optical system arranged so that the reticle scanned is projected on the wafer scanned via the optical unit; and a linear motor being used in the apparatus having, (i) a core member, (ii) a coil obtained by winding a foil-like conductor having an insulating layer around the core member in a multilayered structure; and (iii) a coil fixing portion fixing the coil, wherein the coil is fixed to the coil fixing portion by using the core member.
A maintenance method for an exposure apparatus according to the present invention comprises the steps of: preparing a database for accumulating information about maintenance of the exposure apparatus on an external network outside a factory in which an exposure apparatus is installed; connecting the exposure apparatus to a local area network in the factory; and maintaining the exposure apparatus on the basis of information accumulated in the database by using the external network and the local area network, wherein the exposure apparatus includes a reticle stage scanning a reticle; a wafer stage scanning a wafer; a projection optical system arranged so that the reticle scanned is projected on the wafer scanned via the optical unit; and a linear motor being used in the apparatus having, (i) a core member, (ii) a coil obtained by winding a foil-like conductor having an insulating layer around the core member in a multilayered structure; and (iii) a coil fixing portion fixing the coil, wherein the coil is fixed to the coil fixing portion by using the core member.
Preferably, the exposure apparatus according to the present invention further comprises a display for displaying maintenance information, a network interface connected to a computer network to communicate the maintenance information, and a computer for executing the communication by network software, and the display, the network interface, and the computer enable communicating maintenance information of the exposure apparatus via a computer network.
In the exposure apparatus according to the present invention, the network software preferably provides on the display the user interface for accessing a maintenance database provided by a vendor or user of the exposure apparatus and connected to the external network outside a factory in which the exposure apparatus is installed, and information is obtained from the database via the external network.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.